1. Field of the Invention
The invention relates to a cat litter box with a rotatable container positioned on a frame. The floor of the container forms a collection tray for cat litter, etc., with a mechanical cleaning mechanism positioned vertically in the container and reaching to the floor of the tray, with which waste matter, particularly feces, can be separated from the cat litter when the container is rotated in one direction to clean it and with a storage chamber for the separated waste matter which can be moved together with the container, the entrance to which is arranged in the position of use above the cleaning mechanism.
2. Discussion of the Prior Art
A large number of suggestions exist for cat litter boxes of the prior art which are automatically or semi-automatically cleaned. Known cat litter boxes can be subdivided into two groups according to their function. The first group, which have standing containers and moving cleaning rakes, include for example DE 297 18 260 U1, EP 622 987 B1 and U.S. Pat. No. 5,226,388. Since the cleaning rakes must be moved through the cat litter when it contains waste matter, the power output to be installed for the motor and the forces exerted on the cleaning rakes are relatively high. During the raking procedure, the forces also operate on the clumps of feces, which are bonded only by slight adhesive forces, and which, due to the design, have to be moved over relatively long distances through the clean cat litter, with the result that an undesirable abrasion of the clumps of feces results. The drive and guidance for the cleaning rake are relatively complex in their construction, and difficult to clean and to keep clean in daily use. They severely restrict the freedom of movement of the cat. In addition, corner areas remain which cannot be cleaned or cannot be sufficiently cleaned with moving cleaning rakes.
The invention is based on the second group of cat litter boxes, which have cleaning sieves arranged standing in the container and reaching to the floor of the tray. Cat litter boxes of this type are illustrated for example by U.S. Pat. No. 4,120,264, U.S. Pat. No. 5,402,751, U.S. Pat. No. 5,507,252 and U.S. Pat. No. 5,911,194. They each have a more or less cylindrical housing which is closed all around, and cleaning is accomplished by the housing performing a complete or nearly complete 360° revolution. Cat litter boxes pursuant to U.S. Pat. No. 5,402,751 or U.S. Pat. No. 5,507,252 are thereby constructed as containers which can be rolled off on the floor, while the housings of the other cat litter boxes are housed on a frame. The mechanically simplest solution is displayed by U.S. Pat. No. 5,911,194, which forms the generic starting point.
The generic cat litter box pursuant to U.S. Pat. No. 5,911,194 possesses an upper container part linked to two vertical frame supports. The open underside of the upper part of the container is connected to a floor formed as a tray. This upper part includes an entrance opening, having a closable flap, for the cat. A cleaning sieve is situated in the interior of the container in such a way that it separates around one fifth of the volume of the container as a sector. The container can perform a 360° revolution, in which all the cat litter is retained in the interior. The cat litter falls during the revolution of the container through the lattice sieve into the separate sector, and waste matter and feces remain on the outside of the cleaning sieve. The complete separation of cat litter and feces is accomplished after a revolution of approximately 150° to 180°. The cleaning sieve has a closed plate part which leads into an opening, on the rear side of which a collection bag or similar is stretched as a storage chamber. Through the further turning of the container, the sieved-out feces slip or roll through the sieve onto the plate appendage, from there into the opening, and then into the bag, while the sieved-out cat litter still remains in the separated sector. After completion of a 360° revolution of the container, the cat litter runs a second time through the sieve section of the cleaning rake, while the feces remain behind in the bag. The interior of the bag is to the maximum possible extent sealed off from the interior of the container as a result of the arrangement of the opening leading vertically upwards. The filled bag hangs in the position of use in that section of the cat litter box in which the cat should carry out its business, and it can be exchanged through an access opening in the upper side of the container.
In the use of this cat litter box, soiling of the cleaning sieve and the plate appendage and stronger traces of waste matter in the cat litter appear after a short time. These make excessively frequent replacement of the cat litter necessary. The power output of the drive motor which is necessary for the automatic turning of the container is comparatively high because of the kinematic of the cleaning movement for the cat toilet. A further disadvantage is that the closed construction of the container does not take account of the need of many cats to carry out their toileting in the open.